What to do in the garden in August

What to do in August in the Garden

The last true month of summer the garden and veg plot are still at their best. There is time to sow quick growing salad crops such as Lettuce, Rocket and radish. Deadheading flowers is essential to prolong flowering well into September as the later flowers come to their peak.

If you are going on holiday you still need to look after the garden, especially those plants in containers. For when you are away holiday tips and ideas for looking after plants.

Harvesting crops

Many of the crops are ready to harvest during August and September and it is a priority job to keep harvesting. Picking the veg, in a similar way to deadheading flowers, encourages continued fruiting and so a better yield. After all the hard work of growing the crop, to miss the moment when the beans, courgettes and salads are at their peak is a shame, and easy done at this time of year. The veg quickly go over if not picked regulary, every day or so.

If August is warm, damping down the greenhouse helps to control temperatures. After watering the greenhouse plants, finish off by watering the floor which provides cooling by evaporation, and is best done in the morning to keep the greenhouse cool for the high daytime temperatures.

It is possible to get a second crop of broad beans especially if the summer is good. In late July/early August, when the broad bean plant has finished, cut down the stem close to the ground about 15 cms near a growing point and give it a feed. On a good year it will re grow and produce a second, lighter smaller crop, but perfectly acceptable producing fresh broad beans in late summer/early autumn. Looking at the image left you can evidence of both old and new growth on the broad bean plants, the new growth being produced after the bean has been cut down to aid a second crop; more advice on growing broad beans.

Drying and StoringOnions Garlic and Shallots

Depending on the aspect and geography of your veg plot , Onions, Garlic and Shallots should be ready to harvest by the end of the month,/early September. As soon as the top growth starts to go brown, bend over the top growth, which is said to aid ripening, and then pick a dry spell to ease the bulbs out of the earth carefully before resting them on soil to dry out before bringing in for storage. Onions need to be stored in the light. Garlic is similar, wait till the top growth starts to turn brown usually in late August/Sept. Store in a dry and light spot in the warmth rather than a cold area.

If there is a decent dry spell onions and shallots once harvested can be left on the ground to dry. With our variable weather it can be hard to find a dry spell, and so if the weather is wet, you will need to find another way to dry the onions. It is very important that before the onions are put into storage that they are bone dry, if damp, they will rot and quickly become unusable .

One way to dry off the onions is to bring them indoors, into a conservatory, greenhouse or under glass and dry off in warm atmosphere. The greenhouse is ideal and you can dry them on the slatted shelves as per the image left.

For both onions and garlic, once dried their winter storage requirements are the same; a dry light place and either in net letting air circulate or they can be platted and hung in dry shed/garage/conservatory where they look nice provided you dont mind the onion smell.

Onions and Garlic will store for 12 months in a suitably light dry environment, not the kitchen. For more about harvesting and storing and an easy way to lay them out in the greenhouse check out onions and garlic and the blog

On going tomato care is really important as the plants start to fruit. Tomatoes can produce masses of leaves and it is important to continue to thin these down to encourage fruit production. Even after pinching out the growing points to stop the tomato growing any taller, as tomatoes grow vigorously if allowed, you will need to keep on pinching out all top growth. The plant will keep growing, keep pinching out and removing leaves so all energy goes to the fruit.

This is the most important time for regular watering and feeding to ensure a good crop of sweet tasting tomatoes. Without the right amount of water and feeding, there will be tomatoes, but of poor quality. More about growing tomatoes

There is still enough summer left to sow last rows of lettuces, rocket and crops such as Pak Choy which prefer cooler conditions and will be less prone to bolting (running to seed prematurely because growing conditions are too hot and dry) Any late crops sown during August will need cloche protection later when it becomes cooler.

Maincrop potatoes can be harvested once they have fully flowered and should be ready to harvest in August/Sept. You can leave them in the ground for a while after the top growth has died back. Potatoes already harvested/still being picked are usually the earlies and salad potatoes which will keep fine in the fridge. Maincrops are harvested later and it is essential that they are stored somewhere dry and dark. It is most important when they are put into storage that the potatoes are 100% dry and light is excluded. Hessian sacks are good for storing Potatoes.

Strawberries are all over now and so you can use the runners to make extra or new plants for next year. Let the runners develop and peg down into a pot adjacent to the plant so that when properly rooted in a few weeks the runner can be cut away from the main plant. Strawberry plants need replacing about every 4 years as the yield gets less so this is an easy way to get extra plants; more about growing strawberries

Summer prune Wisteria.

In order to ensure that Wisteria flowers reliably year after year pruning is essential in summer (August) and winter ( Feb) Video tips on how to summer prune Wisteria.

Unless Wisteria is pruned twice a year it will grow very large and almost certainly out grow its allotted space and over time it will cease to flower. Looking at the Wisteria now in August it is always evidence as to the huge amount of growth it has put on over the summer, and it is time to cut off the long wippy growth and all the laterals at the base. This will also ensure the Wisteria does not grow into stonework crevices, drainpipes or anywhere else where it can potentially cause damage.

August is a good time to prune Shrubs which have flowered earlier in the season to shape the shrub, encourage growth and blooms for next year and if they are getting too large for the allotted space. Early August is last chance to prune Weigela, Philadelphus, Choisya, and Wisteria. Late July/August is the best time to give Wisteria it's essential second prune. I often delay to August as in a good year Wisteria will produce a second flush of flowers in July, which although only a few blooms, is still a welcome sight. To ensure that Wisteria flowers it must be pruned correctly and for more about pruning and how to grow Wisteria .

Black spot on Roses

As the summer goes on Roses become more prone to black spot. Blackspot will make the leaves appear yellow and spots appear, some leaves will fall to the ground. Pick up diseased leaves and destroy (not in compost bin) and spray.

Whilst I really do not like to use sprays in the garden, without doubt regular spraying of the roses with a good spray such as 'Roseclear' really does work and the Roses are much healthier as a result. The current produce Roseclear Ultra kills greenfly, blackfly and other aphids. It controls existing infections of the key diseases on roses such as rose blackspot, powdery mildew and rust. It also protects plants from further infestations of aphids and diseases. With the earlier versions of this product it was necessary to every week or two but now the recommended spraying interval is 3 - 4 weeks between applications. I dont have shares in the manufacture of Roseclear, although it sounds as if I do, but it does the job.

Late August is the right time, after flowering, to trim spent flowers from Lavender and clip the plant into neat shape. This will help to keep the plant in a good shape for the next year. The Lavender in the image left has been trimmed each year into a nice round shape and planting by a path is ideal as Lavender release scent on contact, brushing past will produce the lovely Lavender perfume. This variety 'Hidcote' is one of the hardiest of the various Lavender varieties, which can be helpful, as Lavender detest cold wet winters.

Do not trim Lavender stoechas (French lavender) which flowers continuously, just dead head throughout the summer ideas with Lavender

To ensure your summer display continues to bloom for as long as possible, dead head as much as you have time to do. Once a plant has flowered and set seed it will slow down and stop flowering unless prevented by regular dead heading.

Cut back tired looking foliage on Perennials

Even now it is not too late to cut back some of the Perennials which are looking faded, such as hardy geraniums, Nepeta (Cat Mint) Alchemilla (Lady's Mantle.) Cut back to tidy shape and when doing this you may notice, at the base and centre of the plant there is already new growth spurting. After cutting back the plant may, or may not, flower again depending on the weather but it will grow new foliage which will look fresh.

I have cut back Alchemilla almost to the ground around early July and by August the new growth has replaced the old tired browning foliage. I will not flower again but the foliage looks much better and fresher.

Some plants, such as Delphinium may have very tired foliage and cutting them down maybe the only option as the foliage becomes an eyesore.

This is also an ideal time to take cuttings from Pelargoniums and raise plants for free for next year. Easier than most plants to raise from cuttings check out the blog for a guide on how to take cuttings.